DESCRIPTION (Adapted from abstract): This is an AREA grant application that combines both solid-state nuclear magnetic resonance (NMR) spectroscopy and electron paramagnetic resonance (EPR) spectroscopy to investigate the structural and dynamic properties of the membrane-bound protein phospholamban, shown to regulate Ca-ATPase activity in the sarcoplasmic reticulum of cardiac muscle cells. In particular, the orientation of phospholamban will be determined with respect to the lipid bilayer, complementary dynamic information will also be obtained in two different time scale regimes, and new methods for orienting lipid bicelle systems at lower magnetic fields for EPR spectroscopic studies are proposed.